Re: linux-next: manual merge of the tip tree with the FIXME tree
From: Will Deacon
Date: Wed Oct 11 2017 - 13:23:32 EST
Hi Mark,
On Wed, Oct 11, 2017 at 05:10:35PM +0100, Mark Brown wrote:
> Hi all,
>
> Today's linux-next merge of the tip tree got a conflict in:
>
> arch/s390/include/asm/spinlock.h
>
> between a series of commits adding wait queuing to s390 spinlocks
> from the s390 tree:
>
> eb3b7b848fb3dd00f7a57d633 s390/rwlock: introduce rwlock wait queueing
> b96f7d881ad94203e997cd2aa s390/spinlock: introduce spinlock wait queueing
> 8153380379ecc8381f6d55f64 s390/spinlock: use the cpu number +1 as spinlock value
>
> and Will's series of commits removing dummy implementations of spinlock
> related things from the tip tree:
>
> a4c1887d4c1462b0ec5a8989f locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations
> 0160fb177d484367e041ac251 locking/arch: Remove dummy arch_{read,spin,write}_relax() implementations
> a8a217c22116eff6c120d753c locking/core: Remove {read,spin,write}_can_lock()
>
> I'm don't feel confident I can resolve this conflict sensibly without
> taking too long so I've used the tip tree from yesterday.
It's a shame that the conflict is so messy -- most of it is just context
because that file has changed a lot in the s390 tree so the cleanup doesn't
apply. I resolved it below.
On the plus side, it's one less implementation of arch_{read,write}_relax!
Will
--->8
diff --cc arch/s390/include/asm/spinlock.h
index 09e783d83d5d,9fa855f91e55..e31f554a3aa8
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@@ -35,7 -35,7 +35,8 @@@ bool arch_vcpu_is_preempted(int cpu)
* (the type definitions are in asm/spinlock_types.h)
*/
-void arch_lock_relax(int cpu);
+void arch_spin_relax(arch_spinlock_t *lock);
++#define arch_spin_relax arch_spin_relax
void arch_spin_lock_wait(arch_spinlock_t *);
int arch_spin_trylock_retry(arch_spinlock_t *);
@@@ -72,8 -79,9 +73,9 @@@ static inline void arch_spin_lock_flags
unsigned long flags)
{
if (!arch_spin_trylock_once(lp))
- arch_spin_lock_wait_flags(lp, flags);
+ arch_spin_lock_wait(lp);
}
+ #define arch_spin_lock_flags arch_spin_lock_flags
static inline int arch_spin_trylock(arch_spinlock_t *lp)
{
@@@ -105,25 -112,58 +107,8 @@@ static inline void arch_spin_unlock(arc
* read-locks.
*/
- /**
- * read_can_lock - would read_trylock() succeed?
- * @lock: the rwlock in question.
- */
- #define arch_read_can_lock(x) (((x)->cnts & 0xffff0000) == 0)
-extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
-extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
--
- /**
- * write_can_lock - would write_trylock() succeed?
- * @lock: the rwlock in question.
- */
- #define arch_write_can_lock(x) ((x)->cnts == 0)
-static inline int arch_read_trylock_once(arch_rwlock_t *rw)
-{
- int old = ACCESS_ONCE(rw->lock);
- return likely(old >= 0 &&
- __atomic_cmpxchg_bool(&rw->lock, old, old + 1));
-}
--
- #define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
- #define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
- #define arch_read_relax(rw) barrier()
- #define arch_write_relax(rw) barrier()
-static inline int arch_write_trylock_once(arch_rwlock_t *rw)
-{
- int old = ACCESS_ONCE(rw->lock);
- return likely(old == 0 &&
- __atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000));
-}
-
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
-
-#define __RAW_OP_OR "lao"
-#define __RAW_OP_AND "lan"
-#define __RAW_OP_ADD "laa"
-
-#define __RAW_LOCK(ptr, op_val, op_string) \
-({ \
- int old_val; \
- \
- typecheck(int *, ptr); \
- asm volatile( \
- op_string " %0,%2,%1\n" \
- "bcr 14,0\n" \
- : "=d" (old_val), "+Q" (*ptr) \
- : "d" (op_val) \
- : "cc", "memory"); \
- old_val; \
-})
-
-#define __RAW_UNLOCK(ptr, op_val, op_string) \
-({ \
- int old_val; \
- \
- typecheck(int *, ptr); \
- asm volatile( \
- op_string " %0,%2,%1\n" \
- : "=d" (old_val), "+Q" (*ptr) \
- : "d" (op_val) \
- : "cc", "memory"); \
- old_val; \
-})
--
-extern void _raw_read_lock_wait(arch_rwlock_t *lp);
-extern void _raw_write_lock_wait(arch_rwlock_t *lp, int prev);
+void arch_read_lock_wait(arch_rwlock_t *lp);
+void arch_write_lock_wait(arch_rwlock_t *lp);
static inline void arch_read_lock(arch_rwlock_t *rw)
{